A secret key establishment protocol for wireless networks using noisy channels

Article type: Research Article

Authors: Guan, Albert^{; *} | Tzeng, Wen-Guey

Affiliations: Department of Computer Science, National Chiao Tung University, Hsinchu, Taiwan 30010. E-mails: d9955801.cs99g@nctu.edu.tw, wgtzeng@cs.nctu.edu.tw

Correspondence: [*] Corresponding author. E-mail: d9955801.cs99g@nctu.edu.tw.

Abstract: An efficient protocol for establishing secret keys for neighboring nodes in a wireless network is presented in this paper. The security of the key generated by our protocol is based on the unpredictability of the noises in binary symmetric communication channels. The two nodes which try to establish a common secret key receive messages from a common source of random bit strings. Due to noises in the communication channel, the messages received by them, and most importantly the messages received by the eavesdropper, are not the same. We show that the two nodes can modify their messages in an efficient way to obtain a common string which contains enough uncertainty to the eavesdropper. Then, a secure universal hash function is applied to compute a secret key for extracting randomness from the common string. We prove that the probability for the eavesdropper to know the value of the key is negligible. One advantage of our proposed protocol is that the secret key rate is better than the known scheme in other models, such as the bounded storage model. Furthermore, our proposed protocol needs only to perform exclusive-or operations and compute hash values. Thus, it is a computationally light-weight protocol and suitable for devices with limited computing resources, such as sensors in sensor networks.

Keywords: Key agreement, light-weight protocol, wireless network, random noise, binary symmetric channel

DOI: 10.3233/JCS-15807

Journal: Journal of Computer Security, vol. 25, no. 2, pp. 139-151, 2017